JPH072775U - Heat exchanger core - Google Patents

Abstract

(57) [Abstract] [Purpose] The plate of the heat exchange core is a clad material consisting of four layers of a protective layer, a core material, a protective layer and a brazing material layer, and the brazing material layer is brazed by brazing the plate. Even if the residual layer is thinned by being guided to the part, the protective layer on the lower surface prevents corrosion of the core material. [Structure] The heat exchange core 10 is formed by stacking the plates 2 together. The plate 2 is made of Al-Zn alloy layer a, Al-.
The four layers of the Mn alloy layer b, the Al—Zn alloy layer c, and the Al—Si alloy layer d are clad materials, the b layer is the core material, and the d layer is the brazing material. Even if the brazing material layer d is melted and guided to the brazing portion and becomes thin, the core material b layer is protected by the protective layer c layer on the lower surface thereof, so that the heat exchange core has excellent corrosion resistance.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a core of a heat exchanger used in, for example, an oil cooler of an internal combustion engine, and particularly to a material of a plate constituting the core.

[0002]

[Prior art]

 For example, in heat exchangers used for oil coolers of internal combustion engines, plate-shaped plates are stacked and fixed by brazing, and the cavities formed between the plates are used as oil or cooling water flow paths. Those with an exchange core are known. As an example of this, as disclosed in Japanese Utility Model Laid-Open No. 3-30075, a required number of a pair of annular dish-shaped plates having a central opening are alternately stacked in the same direction to form a layered flat chamber. This is a type of so-called housingless type, in which the empty chambers of the lever are alternately used as the flow paths of oil and cooling water.

Further, the core of the heat exchanger disclosed in Japanese Utility Model Laid-Open No. 4-10265 discloses a flat empty chamber formed by stacking a pair of plate-shaped plates having a central opening face-to-face with each other at regular intervals. Are connected to each other, and the interior of the chamber is, for example, an oil flow path and the outer periphery thereof is a cooling water flow path, which is a so-called multi-plate type.

Although stainless steel plates and the like were used for the cores of these heat exchangers, aluminum-based metals have come to be used for the purpose of weight reduction. Conventionally, as the material of the plate, for example, a clad material plate having three layers of JIS alloy numbers 7072 (Al-Zn alloy), 3003 (Al-Mn alloy), and BA4045 (Al-Si alloy) has been used. (Hereinafter, alloy names will be described only by numbers, metal names will be described as aluminum for Al, zinc for Zn, and silicon for Si.)

The Al—Mn alloy layer of the clad material is a core material, and the Al—Si alloy layer is a brazing material.

[0006]

[Problems to be solved by the device]

 When the above plates are superposed, an Al-Zn alloy layer having strong corrosion resistance is present on one surface of the plates, but the Al-Si alloy layer on the other surface is melted to the joint of the plates to be brazed. Since it is induced, the Al-Si alloy remains thin on the surface of the core material.

This Al-Si alloy is susceptible to corrosion due to the segregation of Si at grain boundaries, and since this layer is thin, the Al-Mn layer of the core material does not have a sufficient protective layer and is corroded by the fluid. . This tendency is remarkable on the water side when the fluid is oil and water, and particularly in a place where the flow velocity is high, corrosion is particularly large and sometimes it becomes a hole, and leakage or mixing of oil and water occurs.

[0008]

[Means for Solving the Problems]

 The heat exchange core of the present invention is composed of four layers in which an Al-Zn alloy layer, an Al-Mn alloy layer, an Al-Zn alloy layer and an Al-Si alloy layer are sequentially stacked on a plate constituting the Al-Zn alloy layer. A clad material using a Mn alloy layer as a core material is used, and the joint portion of the plate is brazed with the Al—Si alloy layer.

[0009]

[Action]

 The heat exchange core of the present invention is formed by stacking the plates on top of each other, sometimes further by caulking the edges and brazing them together. In this plate, the Al-Si alloy layer flows out as a brazing filler metal, and even when the Al-Si alloy layer remaining on the plate surface becomes extremely thin, the Al-Mn alloy layer on the lower surface of the plate forms a gap between the Al-Si alloy layer and the Al-Mn alloy layer. Since the —Zn alloy layer exists, even if the remaining Al—Si alloy layer is corroded, the core material is protected by the Al—Zn alloy layer and the progress of corrosion is prevented.

[0010]

【Example】

 The heat exchanger core 1 shown in FIG. 2 is formed by stacking the plates 2 to form an empty chamber 10. The plate 2 has a central opening 3 as shown in FIGS. 3 and 4, and has an annular dish shape having peripheral flanges 4 and 5 on the inner peripheral edge and the outer peripheral edge. An opening 6 is provided for each degree, and an opening flange 7 is provided for two openings 6 facing each other. In addition, a large number of small projections 8 that cause turbulent flow are provided in the flow path inside the vacant chamber 10. The plates 2 are formed by turning the X-X line direction and the Y-Y line direction of FIG. 2 by 90 ° to form a pair, and stacking them alternately to form flat vacant chambers 10 in layers. The opening flange 7 forms two types of fluid flow paths that alternately communicate with each other, and the heat exchange core 1 of FIG. 2 is configured.

As shown in FIG. 1 (Z portion in FIG. 2), the material of the plate 2 is composed of the cladding layers a, b, c and d, and the core material b is 3003 (Al—Mn alloy), The a and c layers on both sides are 7072 (Al-Zn alloy) having excellent corrosion resistance. It has a 4045 (Al-Si alloy) layer on one surface thereof. The 4045 layer is melted when the plates 2 are superposed and brazed to form a brazing filler metal, which is guided to the joint portion of the two plates. Therefore, the plate 2 remains extremely thin on the surface in contact with the fluid.

The example shown in FIGS. 1 to 4 is the housingless heat exchange core 1. FIG. 5 shows an example of the multi-plate heat exchange core 11. A pair of plates 12, 13 having a central opening 3 are laid facing each other and crimped at their edges to form a cavity 14. By fitting the opening flanges 15 and 16 formed in the plates 12 and 13, the respective empty chambers 14 communicate with each other to form, for example, oil passages, and the outer circumference thereof is surrounded by cooling water. The plate 12 is made of the same a, b, c and d layers of clad material as in FIG. 1, and the plate 13 is made of the d, c, b and a layers of clad material.

[0013]

[Effect of device]

 Since the plate of the heat exchange core of this invention is composed of the above-mentioned four layers, the Al-Si alloy layer is introduced as a brazing material to the joint portion of the plate, and even if the surface layer of the Al-Si alloy becomes an extremely thin layer, Since the Al-Zn alloy layer is present on the lower surface and protects the Al-Mn alloy layer of the core material, the heat exchange core has strong corrosion resistance.

[Brief description of drawings]

FIG. 1 is a sectional view showing an essential part of the present invention.

FIG. 2 is a sectional view showing an embodiment of the present invention.

FIG. 3 is a plan view of the plate of the embodiment shown in FIG.

4 is a cross-sectional view (XY line) of the plate of FIG.

FIG. 5 is a sectional view of a main part of a plate according to another embodiment.

[Explanation of symbols]

 2, 12, 13 Plates 10, 14 Vacancy a, c Al-Zn alloy layer b Al-Mn alloy layer d Al-Si alloy layer

Claims (1)

[Scope of utility model registration request] 1. A core of a heat exchanger having a flat empty chamber formed by stacking plate-like plates and fixing them by brazing as a fluid flow path, wherein the plates are made of an aluminum-zinc alloy layer and an aluminum alloy. Mu manganese alloy layer, aluminum-zinc alloy layer, and aluminum-silicon alloy layer are sequentially stacked to form a four-layer clad material with the aluminum-manganese alloy layer as a core material, and the aluminum-silicon alloy layer as a brazing material. A core of a heat exchanger characterized by brazing plates.